Thursday, September 21, 2017

Last Sunday (September 17, 2017) my father passed away at the age of 75 of leukemia. He wasdiagnosed with this cancer only in April and after 5 months, he his now in a better world. As i would say, it's not a farewell but only a "next time" as we all must go one day.

So to my father, see you next time and until then, i'll miss you so much! :(

Monday, January 30, 2017

After posting my attempt on making a Chip-8 game or demo work on the Studio II, Marcel von Tongeren has taken the challenge on adapting the Chip-8 interpreter and on his first try...well guess what folks...It works!

FliP from Atari Age was the first to try out on real hardware and here's the picture to prove it:

In the meantime, i was replying to Marcel on Atari Age (and here afterwards) and here's some text from my reply to Marcel (on A.A.):

... "Oh and i've just seen the post of FliP on Atari Age that he tested your chip8.bin with thegame Breakout and it works! I am so much impressed! This is amazing!

This is quite a step to be able to play Chip8 games on the Studio II and this is yourfirst attemp...totally incredible! You're the main man, Marcel! =)"

And indeed, Marcel is the main man! Way to go Marcel! (Woo!Woo! Woo! Woo! Woo!) (lol!) But also, i wrote (or stated) that for playing his Chip8.bin with a Chip8 game on a Studio II, you would need to perform a small mod to be able to switch off the Studio II interpreter like Flip has done in his picture (check on the left, there's a resistor which has a side loose - that's the R2 resistor between both CS2 (pin #20 on each ROMS) and the Vcc (+5Volts)).

But i can say that i apologize on this statement as i found out that you can play Chip8 games without mofifying any Studio II, you just need FliP's multicart and set Jumpers 1 and 2 (JP1 & JP2) to these settings like on this picture:

Set JP1 to position 2-3 (cartridge kernel) and JP2 to position 2-3 (cartridge TPA) and load on the flash EPROM Marcel's "chip8.bin" from (let's say..) 70000 to 703FF and a Chip8 game (for now, 1K or less in size) from 70400 to max 707FF. That's an example of course as i'm using the last block as the flash EPROM has no games on it.

Still don't beleive this works ? Then check out this video i've made after i discovered that changing the position of the jumpers:

Like i wrote back to Marcel: "I was shitting rainbows as i saw the games working!!" (LOL!!) So Marcel's Chip8 for the Studio II works great even if it needs some tweaks but for a first tryout...Man! It's totally amazing! And remember Marcel, i'll give you a huge hug if i see you in person! ;)

Oh and in the video, there is some Chip8 games that most people never seen or heard. Like i wrote in a previous post, i will post all the Chip8 game i have until now (about 110 and no alternates) very soon. So thanks to Marcel, the game library of the Studio II will increase with time!

I know i have not much posted on this blog, that's because i'm trying to finish my OdySim project but from tme to time, i'm trying to hack or mod something for the Studio II or clones. The last mod i've attempted was a "pause" switch and connecting an Atari 2600 joystick in parallel to keypad A. The pause switch works but i haven't fully tested it to see how long it can "pause" without any kind of bugs.

As for the joystick, well it works...BUT..(yeah a big but) by connecting it in parallel to the keypad A of my Studio II, now it's the keypad who doesn't work. That mod too needs to be checked. But orget those for the moment and concentrate on the subject: Chip-8 for the Studio II !! (and Euro clones also).

I had this idea in my head for a long time, something like 12 years now and seems i wasn't the only person who had this idea (later on). The Studio II is based on a series of 1802 CPU's computers (FRED, Elf, Cosmac VIP, etc...) which all of them have many features in commun with the Studio II. If you look at the ELF or VIP computers (just to name these two), both have a interpreter that people could use which is called: Chip-8.

There's a freaking slew of Chip-8 emulators out there (PC, MAC OS, Android, Java...and so on) and even for many game systems like: Sega Master System, Colecovision, Atari Lynx, Game Boy...etc!! but none for the Studio II..so the big question is ...WHY ??!??

The interpreter (or BIOS) that's built-in the Studio II is very similar, in fact uses many Chip-8 references but it is NOT a Chip-8 interpreter which resides in any Studio II or clones. This interpreter is machine language/Chip-8 mix into one especially for the Studio II. There's a "Programming Cartridge" (aka PROM cart) that Aresco published back then that you could program in machine language on any Studio II..cool but then again, why no Chip-8 interpreter ?

If the Studio II is very similar to Chip-8, then why not make a suited Chip-8 interpreter for the Studio II ?? Let's take the VIP as example. the VIP has a ML interpreter that is 512 bytes (1/2K) and is at memory adress 8000, so you need to load the chip-8 interpreter at adress 0000 and Chip-8 games starts at 0200. Simple enough.

So you need a "monitor" (the VIP BIOS) interpreter and the Chip-8 so Chip-8 game can work. Let's say we use the VIP monitor at adress 0000 to 01FF and the Chip-8 interpreter at adress 0200 to 03FF which makes 1024 bytes (or 1K) of codes taken as each interpreters are 512 bytes. So games would starts at 0400 to ... WAIT!!

You need to know that the last 352 bytes are reserved for stack/variables (from 0EA0 to 0EFF, which equals 96 bytes) and video RAM (from 0F00 to 0FFF, which equals 256 bytes) so games would resides from 0400 to 0E9F (which makes 2720 bytes available).

I tried yesturday a Chip-8 program i've made called "Hello World!) which is a BMP viewer program which looks like this (with Fish 'n Chip emulator - sorry for the small picture, it is 64x32 pixels wide):

The result was for a first try not too shabby as i saw the Earth image in half and the words were inverted (flipped) with many garbled sprites on screen as i used only the Studio II BIOS+original Chip-8 interpreter (ELF or VIP) with the code of the "Hello World" program. It didn't worked like a charm but at least it's a step in the right direction. Oh and i've put this "bundled" code on a RCA Studio II Multi-Cart available from 'FliP" of Atari Age forums.

Since i'm NO programmer (OK.... I know BASIC and LUA - big Whoop!), is there someone who knows ML/Chip-8 languages for the CDP1802 and could do a Chip-8 intreperter made for the Studio II ? That would be SSOOO AWESOME!!

Because this would extend the game library of the Studio II not to 30 or 40 games but more than 200!! Yup, i'm not joking as i cataloged more than 200 Chip-8 games which this list contains NO alternate versions or program/demos. I have so far 109 Chip-8 games in ".c8" format and i'm missing about 125 Chip-8 games which are still either not typed and saved in c8 format or missing the listing. I will post my list very soon with all the Chip-8 games i've collected so far.

Thursday, August 11, 2016

"I am glad that the Studio II is finally getting some credit. Would it be possible to make a studio II flash cart?"

Hi Kavi,

I can do a multigame cartridge with dip switches but doing a Flash cart ? That i don't know and i don't see why to do a Flash cart since there is almost no homebrew dev on the RCA Studio II & clones sides, but on the side of Chip-8 then this would be a great idea since there is from time to time new homebrews for it.

There are not so many homebrews for the Studio II (and clones) and many were done by Paul Robson so i think the best would be doing a EPROM multigame cart with dip switches and if there would be a version 2, a menu-driven would be awesome but i don't know how to program for the Studio II.

Blazing Lazers of AtariAge posted a picture of the programming manual of the RCA Studio III, which is all the European clones (except for the Toshiba Visicom which has a different color circuit). If ekeefe (the guy who has the Studio III manual) could scan the manual and released it as a PDF file, this would be so great since we will surely see new homebrews in color in a near future.

Well the picture i've uploaded on the forum has vanished into oblivion, but fear not! Here's the original picture:

So since it's pretty late and i'm beginning to be sleepy (and lazy at the same time...lol!), i'll copy-paste what i wrote of the forum:

"It is really simple actually, you will only need to solder (or tie
together...not the best thing but only do this if you don't have a solder iron) 3 wires! One for the video, one for the audio and one for the ground. At first when i've opened the console, i was hesitant since everything written is in Japanese but once i saw only seven wires connected to the RF modulator, it was much easier than to translate...lol!

There is three yellow wires which are connected to a switch, these three you can cut since it's only for channel 1 & 2 and you can also cut the wire next to the yellow indicated by a weird "N" symbol (that one is the +5V). Now that four wires are cut, there is only three left (those that we need). Now cut those three and solder/wire them to the appropriate output (video = yellow, audio = red and ground ....is ground! lol!). Voila! Told you guys that it was simple!"

And this is no joke, it is actually one of the simplest mod that can be done. So for the next A/V mod, it will be M-1200/MPT-02 clones as "phreak97" (from Atari Age forums) is testing out the A/V mod
on a Soundic Victory MPT-02 (and another Soundic for "space_man73") and it's going great!

Oh and i have almost finished the schematic of the color circuit for all M-1200/MPT-02, this will be a great help to understand how it's done and how to make a good A/V mod. =)